An operating system manages computer hardware, software resources, and provides common services for programs.

The price of reliability is the pursuit of the utmost simplicity. It is a price which the very rich find most hard to pay.~

Time is valuable and ten seconds' worth of it is well worth the investment of a day's happy activity working out a way of saving it. Douglas Adams
unix — Static
Hilbert in Smalltalk-80
smalltalk — Hilbert in Smalltalk-80
Neauismetica on Macintosh
macintosh — Neauismetica on Macintosh
plan9 — Catclock